Yep, as Sean said I assumed that you use SQL 2012 and windows offset functions are a good choice in situations where you want to refer to some other row from your row.
Anyway, if you cannot use SQL 2012 the following query is logically equivalent to the query I provided in previous post:
CASE WHEN DATEDIFF(DAY, Date2,
SELECT TOP 1 Date1
FROM YourTable t2
WHERE t1.IDNo = t2.IDNo AND t1.RowId < t2.RowId
ORDER BY t2.RowId ASC
) < 14
FROM YourTable t1
ORDER BY RowID
Do Not Optimize for Exceptions!